1. Field of the Invention
The present invention relates to a filtration apparatus that removes chips from a chip-containing machining fluid such as a grinding fluid or cutting fluid used at a machining center, for example, and is particularly intended to effectively prevent clogging of a filtration filter that makes up the apparatus.
2. Description of the Related Art
Filtration apparatuses are conventionally used as means for removing chips from a chip-containing machining fluid such as a grinding fluid or a cutting fluid used at a machining center. Filtration apparatuses disclosed, for example, in Japanese Patent Application Laid-Open No. 2012-143833 and Japanese Patent Application Laid-Open No. 1-139113 are known as such types of filtration apparatuses.
The filtration apparatus of Japanese Patent Application Laid-Open No. 2012-143833 adopts a configuration of housing a chip conveying member (2) in a chip conveying member housing (1) and providing an input port (3) and an ejecting port (4), a configuration of conveying chips in a machining fluid (used cutting fluid) inputted through the input port (3) up to the ejecting port (4) using the chip conveying member (2), a configuration of causing the machining fluid to flow into a rotary filtration drum housing (5) from the chip conveying member housing (1) through an inflow side (10) and filtration filtering the machining fluid using a filtration drum (6) that rotates in the rotary filtration drum housing (5), a configuration of scraping the chips deposited on a bottom surface of the rotary filtration drum housing (5) using a scraper conveyor (12), and a configuration of sending the scraped chips from a baffle plate (11) in a direction of the chip conveying member (2).
In the filtration apparatus according to Japanese Patent Application Laid-Open No. 2012-143833 that adopts the above configuration, of the chips in the machining fluid introduced from the input port (3), relatively heavy chips are deposited on the bottom surface of the chip conveying member housing (1), conveyed up to the ejecting port (4) via the chip conveying member (2) and finally ejected to the outside from the ejecting port (4).
However, according to the filtration apparatus in Japanese Patent Application Laid-Open No. 2012-143833, when chips floating in the introduced machining fluid (hereinafter referred to as “floating chips”) exist as described above, such floating chips unavoidably enter the rotary filtration drum housing (5), and the introduced floating chips may be stuck to a filtration filter on an outer circumferential surface of the filtration drum (6), causing clogging of the filtration filter with the chips.
On the other hand, the filtration apparatus according to Japanese Patent Application Laid-Open No. 1-139113 adopts a configuration of arranging a magnet (20) on a bottom surface (1B) of a cutting fluid input tank (1) and fixing floating chips to the bottom surface (1B) of the cutting fluid input tank (1) through a magnetic force of the magnet (20) and a configuration of scraping the fixed floating chips from the bottom surface (1B) of the cutting fluid input tank (1) using a scraper plate (7A).
To solve the problem with the filtration apparatus of aforementioned Japanese Patent Application Laid-Open No. 2012-143833 (clogging of the filtration filter with chips), the technique of fixing floating chips by a magnetic force of the magnet (20) disclosed in Japanese Patent Application Laid-Open No. 1-139113 may be applied to the filtration apparatus in Japanese Patent Application Laid-Open No. 2012-143833.
However, Japanese Patent Application Laid-Open No. 1-139113 has no description taking into consideration the influence of the magnet (20) in the periphery of the inflow side (10) as to how the magnetic force of the magnet (20) acts in the periphery of the inflow side (10) of the filtration apparatus of Japanese Patent Application Laid-Open No. 2012-143833.
For this reason, with the filtration apparatus described in Japanese Patent Application Laid-Open No. 2012-143833 employing the floating chip fixing technique using the magnetic force of the magnet (20) disclosed in Japanese Patent Application Laid-Open No. 1-139113, a floating chip returning phenomenon and a floating chip re-fixing phenomenon which will be described below occur in the periphery of the inflow side (10) repeatedly, causing the floating chips to circulate.
<<Floating Chip Returning Phenomenon>>
The floating chip returning phenomenon refers to a phenomenon that in the filtration apparatus described in Japanese Patent Application Laid-Open No. 2012-143833, floating chips are fixed in the vicinity of the top edge of an inclined extension plate (8) located in the periphery of the inflow side (10) by a magnetic force of the magnet, the floating chips fixed in this way are scraped by the scraper conveyor (12) and returned to the chip conveying member housing (1).
<<Floating Chip Re-Fixing Phenomenon>>
The floating chip re-fixing phenomenon refers to a phenomenon that in the filtration apparatus of Japanese Patent Application Laid-Open No. 2012-143833, the floating chips returned as described above flow into the rotary filtration drum housing (5) riding on the flow of the machining fluid directed to the rotary filtration drum housing (5) from the chip conveying member housing (1) via the inflow side (10), and are re-fixed in the vicinity of the top edge of the extension plate (8) by the magnetic force of the magnet.
With the filtration apparatus described in Japanese Patent Application Laid-Open No. 2012-143833, even when the floating chip fixing technique by the magnetic force of the magnet (20) disclosed in Japanese Patent Application Laid-Open No. 1-139113 is applied, circulation of the floating chips occurs in the periphery of the inflow side (10) as described above, and therefore the circulating floating chips may deviate from the circulation path and arrive at the filtration filter on the outer circumferential surface of the filtration drum (5), increasing the likelihood of clogging of the filtration filter with the chips.
Note that the parenthesized reference numerals are reference numerals used in respective Japanese Patent Application Laid-Open No. 2012-143833 and Japanese Patent Application Laid-Open No. 1-139113.
The present invention has been implemented to solve the above problems, and it is an object of the present invention to apply a filtration apparatus that removes chips from a chip-containing machining fluid and effectively prevent clogging of a filtration filter that makes up the filtration apparatus.